Seafloor bacteria are multi-tasking with the carbon cycle

SHARE THIS:

March 22, 2007Scientists have long known that microorganisms can use one of two
different methods to convert carbon dioxide into a form that living
things can use for energy. What they didn’t know until recently is that
at least one form of bacteria can switch between these two “carbon
fixation” pathways or use them both at the same timea fundamental
discovery for scientists who believe such bacteria played a role in the
evolution of life on Earth. Past research has shown that symbiotic
bacteria live inside tubeworms and provide energy to their hosts in
exchange for a safe place to live. Biologists knew this marriage was a
good one, as the tubeworm is the fastest-growing marine invertebrate
known to exist. But they did not know the details of how the bacteria
make the energy because they could not culture the bacteria
successfully in the lab. WHOI microbiologist Stefan Sievert was part of
a research teamled by Thomas Schweder and Stephanie Markert of the
Institute of Marine Biotechnology in Germanythat studied the
bacteria’s genome to discover how these microbes switch back and forth
between both carbon-fixing methodsthe “Calvin cycle” and the reductive
tricarboxyclic (rTCA) cycleto adapt to fast-changing environmental
conditions on the deep seafloor.

Scientists have discovered that the endosymbiotic bacteria living inside tubeworms are capable of using two fundamentally different means to generate organic carbon--both the "Calvin" cycle and the reductive tricarboxylic acid (rTCA) cycle. (Photo by Woods Hole Oceanographic Institution)

See Also

The Sievert Microbial Ecology & Physiology Lab studies the composition and function of microbial communities, with the goal to understand the relationship between microorganisms and their biogeochemical transformations. Special interests include chemosynthetic processes that are important in a variety of environments, including hydrothermal systems, oxygen minimum zones, and sulfidic marine sediments.

The Woods Hole Oceanographic Institution is dedicated to research and education to advance understanding of the ocean and its interaction with the Earth system, and to communicating this understanding for the benefit of society. Learn more »